Wood-pulp-grinding machine



May 6, 1930- w. A. wHlTcoMB 1,757,031

'QCD PULP GRINDIHG CHINE l Filed Jan. 15, i925 :s sheets-sheet 2 May 5,1930. w. A. wHlTcoMB 1,757,031

WOOD PULP GRINDNG MACHINE Filed Jan. 15, 1926 3 Sheets-Sheet 3 W l l. Q912g Jiu/erzhlt all Patented May d l93 einen eater WILLAM W'HITCOMB, QFDEDLEAM, MASSACHUSETTS, ASSEGNOR TG GREAT NRTIS- EEN EPER COMPANY, 0FMILLENOCKET, dl'l, CGRPGRATEON @E MAINE WOD-LBULP-GRENDNG MELHENE.Application filed January l5, 1926. Serial No. Stdt?.

rl`his invention relates to paper making und has particular reference toautomaticlced grinding machines for making ground wood pulp.

lt has been proposed heretofore to provide Wood pulp grinding machineswith means automatically to eed wood to the action ol the grindstone.Suchgrinders have not been a commercial success mainly because the Woodwould form a self-supporting bridge or arch that would prevent furtherfeeding action until the arch-formation was broken up by an attendant.The formation oi an arch also prevented the application of pressure onthe grindstone, so that the grindstone would race and sometimes burst.V

l have found .that a grinder can be ted automatically with entiresuccess il the wood is ted in successive and premeasured charges to theaction of the grindstone. the machine being fed automatically with a newmeasured charge only when the previous charge had been about ground out,and each charge being relatively small and fed through a wide openinginto the space between the grindstone and the pressure-toot of thepressure cylinder, so that possibility of arching and consequentnon-feeding of the 'charge is almost entirely, it not completely.avoided. rlhis constitutes one of the objects oi my present invention.

A further object of this invention is the provision of a magazine-typewood pulp grinder so arranged that successive charges of wood are tedautomatically into position to be acted upon by the grindstone, andwherein the main duty of an attendant is to place new charges-of Woodinto the magazine, when it is empty, the machine otherwise beingcompletely automatic'in operation.

A further object is to provide a magazinetype grinder with a magazineadapted to hold only a single charge of wood, withautomatically-operative means to admit the charge into position betweenthe grindstone and the pressure-foot, and to apply pressure on thecharge, following the exhaustion of the previous charge.

A yet further object of the invention is the provision of adouble-pocket grinder,

means to iteed the charges :into grinding position, the arrangementbeing such that the grmdstone may always be loaded., and racingprevented.

' A yet further object is generally to improve the construction andoperation of wood pulp grinders.

F ig. l is a side elevation of a magazine grinder embodying myinvention, parts thereof bein broken away to show certain features olinternal construction.

Fig. 2 is a plan view of Fig. l.

Fig. 3 is a sectional elevation through one of the pressure-cylindersand magazine, taken along line 3 3 of Fig. 2.

Fig. 'd is a sectional detail taken along line fe-d of Fig. 3.

Fig. 5 is an enlarged sectional detail through the automatic-controlrod, taken along line 5--5 of Fig. 2.

Fig. 6 is a. detail oit the operating mecha nism of the door-operatingvalve.

rlhe magazine-feed wood pulp grinder embodying this invention includesan enclosing housing l0 in which the grindstone 12 is disposed. Saidgrindstone is carried by a shaft 14 which is iournalled in bearings 16and is driven by suitable means, not shown. A. casing 18 ofapproximately rectangular internal cross-section is secured to each sideof said housingvl() and extends upwardly and outwardly therefrom andco-aXially with radii of the grindstone. The interiors of said casingsform pockets in which the Wood is retained while it is being ground andthev grindstone forms the end walls of said pockets. Pressure-feet 20are disposed movably in said pockets, there being tWo in each pocket.Said presure-eet are arranged to occupy practically the entirecross-sectional area of said pockets and to apply a pressure on the woodin said pockets. Pressure is applied to said pressure-feet by means ofhydraulic cylinders 22 which are secured to the outer ends of saidcasings and in line therewith. As here shown, a pressure-cylinder isassociated with each pressure-foot. Pistons 24 lUll are contained withinSaid cylinders and arc connected with said pressure-feet by pistou rods26. lVhen a pocket'contains a charge of wood. water at a suitably highpressure. is admitted into the outer e'nd of the cylinders. The pistonsand pressure feet are thereby moved inwardly toward the grindstone andinto pressure-engagement with the wood in the pocket, thereby to forceand hold the wood onto the revolving stone and cause it to be groundinto pulp fibres. When the charge of wood is about ground out, thepressure-feet are withdrawn into the upper ends of the pockets inposition to receive a new charge between them and the grindstone.

The-above constitutes the construction and arrangement of the usual woodpulp grinder.

In accordance with my invention I provide means to move thepressure-feet automatically up and down the pocket and means tointroduce a premeasured charge of wood into the pocket when the pressurefeet are in the upper end. of the pocket, whereby automatically to loadthe machine for further grinding operation.

I'n carrying out my invention I provide each pocket 18 with a magazineor hopper 28 which is disposedu above the pocket and is approximatelyco-extensive with the width and length thereof. Said hopper is providedwith side and end Walls 30.

The hopper is open at the top and has approximately the volume of thepocket with which it cooperates so that, when the hopper.

ranged to be in the closed position shown in Fig. 3 when the wood in the-pocket is being ground. The door is adapted to be slid to the left,Fig. 3, upon the pocket-casing when the pressure-foot is in its upperposition, and to uncover practically the entire bottom area of thehopper, whereby to permit the charge of wood contained inthe hopper tofall freely into the pocket. Since the hopper has vertical side walls.and is immediately over the pocket and is approximately an extension ofthe pocket, the charge of wood in the hopper is free to fall freely intothe pocket, without arching or jamming Vin any manner. After the chargeof wood is delivered into the pocket the door is adapted to close, andpressure is applied to the wood.

The two pockets and hoppers are adapted to be Worked so that there is acharge of wood in one hopper at the time a charge is being loaded intothe other hopper'. As thus arranged, it is ,practicallyl certain thatthere will always be a load on the grindstone and that racing will beprevented.

The hopper-doors are opened and Closed by means including hydrauliccylinders 34, which cylinders are mounted upon and between the pair ofcylinders 22 associated with each pocket. Piston rods 36 serve toconnect the pistons within said cylinders 34 with the doors. v Thearrangement is such that when water under pressure is admittedalternately to the inner and outer ends of said cylinders, the doors arecaused respectively to open and close.

Means are arranged to operate the pressure-feet and hopper-door of eachpocket automatically in timed sequence, whereby to effect the automaticoperation of the machine, the only necessary manual o eration being toload successive charges op wood intov the empty hopper. The arrangementof said means is such that'. when the wood 'in the pocket hasbeen ground-out to a predetermined extent, the ressurefoot is caused to operate ahydraulic valve which effects the raising of the pressure foot. Whenthepressure foot is about in its highest position, it is caused tooperate .mechanism to open the slid` ing door. When the door is about inits wide open position it effects the operation of mechanism to causethe pressure foot to move inwardly. The beginning of downward movementof the pressure foot causes the door to close, thereby effecting a cycleof operation. The speed of movement of the door` in closing is adaptedto be considerably greater than the speed of inward movement of thepressure feet so that the door completely closes before the pressurefeet are moved sufhciently to apply any material degree of pressure onthe charge of wood in the pocket.

The means for effecting the above described cycle of operation includesa pair of rods 38 and 38a, which rods are attached to one of thepressure feet at the upper end thereof and are extended outwardlythrough the top of the pocket-casing. The rod 38 is provided with asleeve 40 which is loose on said rod. Said sleeve is provided with alongitudinal slot 42 therein in which a pin 44 fixed to'the upper end ofsaid rod 38 can operate. A ring 46 is. disposed on an intermediatesection of said sleeve and can be fixed in any desired longitudinalosition thereon. provides means by which the opening of the door effectsthe downward movement of the pressure feet in a manner hereinafter to befurther described. Said ring 46 is provided' with an internal slot 48therein which is disposed in line with the slot in the sleeve 4() sothat the pin 44 carried bv the rod 38`can pass freely from one side tothe other of said ring Without engaging it. Said ring is also providedwith an opstanding pin 50 which is adapted to be vengaged by the door inthe last part of the opening movement thereof.

A secondring 52 is secured adjustably on said sleeve 40 -at the lowerend thereof and is roo Sald ring l position. therebv to move the sleevedownwardly toward the left, Figs. 2 and-5.

A lever 54 is pivotally connected b means "including pins 56 with thelower en of said sleeve and is adapted to .be moved in accordance withthe movements of said sleeve. Said lever is arranged to operate ahydraulic valve 58 which receives water under suitably high pressurethrough the inlet pipe 60. Said valve 58 is arranged to control themovements of the valve-pistons in a pair of valves 62 by admitting waterto one side or the other of the pistons in the cylinders 63 associatedwith said valves. Each of the pair of cylinders is provided with a valve62 and said valvesare arranged to control admission of water to theinner and outer ends of the cylinders 22 whereby to effect,respectively, the outward and inward movements of the pressure feetassociated with said cylinders. Each valve 62 is connected by a pipe 64to the inner end of its cylinder and with another pipe 66 to the outerend of its cylinder, the connections bein v more or lessdiagrammatically shown. Higli pressure water may enter the valvesthrough the pipes 67, connected with the pipe 60, and grinder pressurewater through the pipe 69. Exhaust water is adapted to escape throughthe pipe 68. The arrangement is such that when said lever 54 is movedinwardly or toward the left by the engagement of thc pin 44 with thesleeve 52, water is admit-ted to the cylinders 63 of the valves 62 to'move the pressure feet away from the grindstone. When said lever ismovedV toward the right, the valves 62 are operated to admit water in adirection to move the pressure feet downwardly towards' the grindstone.A

The door-operating cylinder 34 is provided with a control valve 70 whichis connected to the source of high pressure water by a pipe 72 aml totheexhaust throu h a pipe 74.

Said valve may be of any suita le type which is arrangedwhen moved inone direction to open the door and when moved 1n the other direction toclose the door. The valve is provided with an operating member having apair of spaced arms 76 and 78, see Fig. 6. A pin 80 is carried by thepressure-foot rod 38 at theupper end thereof. Said pm is adapted toengage alternately with said arms whereby toietlect the alternate andopposite operation of said valve, and consequently, the opening landclosing' of the door.

The complete cycle of operation 1s substantially as follows: When thepressure foot is about at its lowest point of travel 1n the pocket, thelever 54`is operated in a direction to admit water to the inner ends ofthe cylinders 22 and thereby to move the pressure feet upwardly in thepocket. At about the extreme end upward movement of the pressure footthe pin 80 carried by the rod 38" engages the arm 78 of thedoor-operating cylinder-valve 7 0 and operates said valve in a man- Yner to open the door and. consequently. to admit the charge of wood fromthe hopper into the pocket. When the door Ss about. in`

its extreme open position, its edge engages the pin carried by thering46 of the slee 'Je 40, and causes the reverse movement of the lever54. This action admits water into the outer ends of the pressurecylinder-S22 and thereby starts the inward, or working stroke, of thepressure feet.- However. before the pressure feet have moved inwardlyany material distance. the pin 80 carried by the pres-l sure foot rod 38is moved inwardly and into engagement with the arm 76 of thedooroperating valve 70. Said valve is thereby operated to close thehopper door. The inward`movement of the rod 38a causes the pin 80 tomove from under the arm 76. which arm is adapted to remain in saidposition, as illust-rated in the dottedglines in Fig. 6, until it isagain operated in thei reverse direction.

'hile the inward movements of the pressure feet and the hopper v doortake place sinmltaneously, the hopper door is arranged to move fasterthan the. pressure feet so that the door is completely closed before anymaterial degree of pressure is exerted on the new charge of wood in thepocket; During the grinding of the charge of wood in the pocket, anattendant is required to refill the hopper with another charge of woodso that there will always be a full hopper at the time the wood in thepocket is about ground out.

As here shown, both sides of the machine is adaptedto operateindependently of each other. One side of t-he machine, however, isadapted to be started up ahead of the other side so that the hoppers areemptied alternately. As thus operated. it. is quite improbable that bothpockets will be. emptied at the same time so that there will always` bea load on `the grinder and racing will be prevented.

1, A wood pulp grinding .machine having a grinding pocket, a pressureelement movable forwardly and backwardly within said pocket, a hopperassociated with said pocket, a door controlling communication betweensaid hopper and pocket, means controlled by said pressure element tooperate said door, and means controlled by said door to operate saidpressure element.

2. A wood pulp grinding machine having a grinding pocket,`a pressureelement mov-v able forwardly and backwardly within said pocket, a hopperassociated with said pocket, a door controlling communication betweensaid hopper and pocket, and means to move lsaid pressure elementbackwardly and thereafter to open said door.

3. A wood pulp grinding machine having a grinding pocket, a pressureelement movable forwardly and backwardly within said pocket, a hopperassociated with said pocket, a door controlling communication ,betweensaid hopper and pocket. means governed by saidpressure elementvwhen atone end of its path of travel to open said door. and means 'governed bysaid door to move said pressure element forwardly.

4. A wood pulp grinding machine having a grinding pocket, a pressureelement movable forwardly and backwardly within said pocket, a hopperassociated with said pocket, a door controlling communication betweensaid hopper and pocket, means actuated by the pressure element in itsextreme back Ward position to open said door, and means actuated bytheopening movement of said door to close it and also to move saidpressure element forwardly.

5. A wood ulp grinding machine having a grinding poc et, a pressureelement movable forwardly and backwardly therein, a hopper associatedwith said grinding pocket, a door controlling communication betweensaidhopper and pocket, means including a valve controlled by said .pressureelement and also by said door for moving said pressure element forwardlyand backwardly, and means including a second valve controlled by saidpressure element alone for opening and closing said door.

6. A wood pulp grinding machine having a grindstone, a grinding pocketat the grindstone, a pair o pressure elements reciprov -cable in saidpocket to press the wood against ing a grindstone, a grinding pocket atthe.

grindstone, a pressure element reciprocable `in said pocket to press thewood against the grindstone, a' hopper disposed above'A the pocket andopening thereinto, and a door at the bottom of the hopper above thepocket .operable independently of said pressure element arrangedV toopen to ermit a charge of wood to fall by gravit Prom the hopper intothe pocket when sai pressure element is withdrawn and to close above andout of pressure-applying engagement with the charge of wood in thepocket.

8. A wood pulp grinding machine having a grindstone arranged to rotateon a horizontal axis, grinding pockets oppositely disposed with relationto the periphery of said grind- A stone, a-hopper above each pocketadapted to contain a charge of wood for the pocket, a

sliding door` between each ho per and pocket 'arranged to slide open toadiin 't a char e of wood into the pocket and slide shut a ve thoiocketand above and not against lthe w to be ground, and pressure meansoperable independently of said doors to press the wood in the pocketaaiiinst the grindstone.

9. A wood pulp grin ng machine having a grindstone arranged to rotate on,a hori-v posed with relation to the perip grindstone, a ho per aboveeach pocket adapt-A ed to contain a c arge of wood for the pocket,

zontal axis, grinding pockets oppositely disery of said a sliding doorbetween each hopper and pocket arranged to slide open to admit a chargeof wood into the pocket and slide shut above the pocket without pressingthe wood against the grindstone, and ress'ure means operableindependently of said) doors to ress the wood inthe ockets against thegrin stone.

10. wood pulp grinding machine having a grindstone rotating lon ahorizontal axis,

, grinding pockets disposed on opposite sides of the grindstone.-hoppers disposedimme dlately above each pocket and havin proximatelythe ca acity of said poc et, a

sliding door contro ling communication between each hopper and itscorres nding pocket, and pressure means for eac pocket located entirelybelow the plane of the sliding door of the -pocket to press the wood inthe pockets against the grindstone, said doors and said pressure meansbeing independently movable.

In testimony whereof, I have signed my name to this specification.

WILLIAM A. WHITCOMB.

